You're a younger child, 4 or 5. You have a lot of sleepovers at your friends' or relatives' houses. You always get excited when your parents tell you that next week you're going to be spending the night somewhere else, and you don't understand why other kids feel homesick when they're away from their parents. You're always shuffled from one house to the next, and you handle it just fine, thanks! Occasionally your parents go on vacations and trips, but you don't get to go. That's fine, theyre going to do boring adult stuff anyway. Still, it would be nice if you could go with them sometime, but its just that you're too young now, you'll surely get to go when you're older.
Now you're an older child, 9-10. You're wondering why some family friends are no longer around, and why you haven't been invited back to some kids houses after you used to stay the night so much. Your last sleepover seemed rushed, your parents started getting ready to go out after you got home from school, and they called the parents of one of your friends to arrange for you to stay with them, even though it's a school night. That night, you overhear your friend's parents saying something about how ridiculous it is that they (your parents) keep doing this, why is this more important than watching their kid? You wonder what "this" is. You wonder why you never go out to do anything with your parents on the weekends. They're still taking trips without you, but now you see your friends at school coming home from family vacations, and you don't know why your parents are never able to make the time.
Your childhood is lonely. You have your friends, yes, but your parents are always in and out, because unbeknownst to you, you came second to them getting some strange. Their choices have caused you to lose friends because they caused you to wear out your welcome in other kids' houses, or because the other parents were disgusted by your parents' behavior. God forbid you ever find out about your parents' second lives in the future, because now every lonely moment, every weird comment from your childhood, every question you ever had about why your parents were not there is answered: they wanted to fuck more than they wanted to be around you. Everything is recontextualized, and even the good memories of spending time at friends houses and staying up til dawn are tinged with the realization that your parents only did that so you wouldn't get in the way of their sexual proclivities.
And this assumes that they were perfect at concealing their *ahem* lifestyle from you, that there was no additional kink shit around for you to stumble upon, that your friends/kids at school didn't know.
It makes me sick, because honestly? This is probably the best outcome for a kid whose parents are into this shit, and it still leaves a kid who feels lonely and unloved.